Refrigerator control



3 Sheets-Sheet l 1x: 'ENTOR.

P2775250 779mm? gd/w w .4 TTORXEY.

P FARMER REFRIGERATOR CONTROL Filed Nov. 27 1935 vm ani V .5:

5:1 W & i

June 16, 1931.

June 16, 1931. P. FARMER 1,809,923

REFRIGERATOR CONTROL Filed Nov. 2 1925 3 Sheets-Sheet 2 INVENTOR.

Erna/2:0 Foe/wee June 16, 1931. P. FARME'R 1,809,928

REFRIGERATOR CONTROL Filed Nov. 27, 1925 s Sheet-Sheet a IIIIIIII INVENTOR. 297755150 file/vase A TTORNEY.

Patented June 16, 1931 a or nn'rrr,

REFEIGERATUR m 1:; 0.

Application filed. November 2?, 1925. Serial Ito. 71,850.

lhis invention relates to a refrigerator control which is especially adapted for use with electro-mechanical refrigeration. Such a control as I am about to describe is particu larly adaptable in a fluid expansion type of thermostat where temperature changes aflect a volatile fluid in said thermostat which expands or contracts the fluid, thereby actuating a switch to turn the same on or ofl for re Eur-fining the refrigerating apparatus on or One of the objects of this construction is the construction of a control whereby a more frequent operation of the machine and shorter operating time during each period of operation is obtained. This results in the maintaining of a more constant temperature in the refrigerator and does not permit of a wide variation in temperatures, such as is common in most of the electro-mechanical refrigerators now on the market.

Fig. 1 is an elevation of my control assembled with a conduit bearing the expanded gases of a refrigerating apparatus.

Fig. 2 is a vertical section on the line 2-2 of F1g. 1.

Fig. 3 is a section through a modified form of casting that is included in the conduit and supports the thermostat.

Fig. 4 is an additional modified sectional view showing means for regulating the convection currents.

Fig. 5 is a plan view of another modified form of casting showing a relatively long coiled feeler leg.

Fig. 6 is a section on the line 6-45 of Fig. 5.

Fig. 7 is a plan view showinganother modified form of construction. i

Fig. 8 is a section on the line 8-8 of Fig. 7.

Fig. 9 is a vertical section showing a modified form of non-expansive chamber secured to the thermostat.

Fig. 10 is a transverse section through a modified form of feeler leg.

Fig. 11 is a front elevation of a refrigerator with the door to one of the compartments opened to show the installation of the refrigerating unit therein.

Fig. 12 is a cross section showing a modified construction of thermostat.

In refrigerating apparatus which uses a refrigerant and which operates on' the fluid expansion principle, a designates the usual conduit which bears the expanded gases from the expansion coils 2 of the refrigerating apparatus. Secured in this conduit line is a casting or fixture 6, preferably circular in plan, and provided with the circular passageways c, and the circular opening d. These passageways are in communication 1 with the conduit line and it may be plainly seen how the gases passing through the conduit line, would divide and be conducted around the central opening in the casting.

l have provided a usual thermostat 6 provided with the expansive chamber 7", preferably constructed by the use of a bellows. Depending from the thermostat is a casting 9 (see Fig. 2), which forms a non-expansive chamber in and which is of such a size as to 70 drain all the condensed fluid from the bellows. As the temperature rises this volatile fluid will vaporize and fill the expansive chamber or bellows and move the switch arm 11 which is adapted to be connected to any suitable form of electric switch, (not shown). 1

This casting g isarranged to fit snugly in the central opening 0? and the flanges j of the thermostat are adapted to seat on the upper part of the casting b, and the joint is tight enough so as to prevent the passage of any convection air currents past said joint.

1 preferably form the wall of the passageway c, adjacent the central opening, relatively thin so as to permit the ready transference of heat through the wall. The temperature of the casting q is thus controlled by a direct conduction of heat from the fluid in the conduit through these relatively thin walls in other words the heat exchange is eflected through a metallic contact. As an aid to the heat from the fluid in the thermostat into the conduit a bearing the expanded gases. An equivalent construction would be similar to that shown in Fig. 9'where the casting g is replaced by a sleeve m secured to the thermostat and which is plugged up by the plug n. structed with this inserted wall of sheet cop per or other material and used in conjunction with the form of feeler leg or expansive chamber, such as is shown in Fig. 9.

In Fig. 4, I have shown how the shutter 0 may be secured by means of screws 79 to the bottom of the casting b for varying the size of the opening d at the bottom of this cast-ing. Obviously, the bottom of the non-expansive chamber is exposed to convection currents from the bottom as this central opening is normally opened, but by means of the shutters 0 I may cut down the size ofthis opening or close the same completely to thereby regulate the amount of convection currents that may pass. The regulation of these convection currents may be had by securing various sized shutters to the casting, larger sized shutters being designated by the dotted lines q in Fig. 4.

In Figs. 5 to 8 inclusive, I show other modified forms of construction in which the casting 9 is replaced by a relatively long coiled feeler leg 1'. This coiled feeler leg may be a circular coil, as shown in Figs. 5 and 6, or may be substantially a rectangular coil as shown in Figs. 7 and 8. The casting b is shaped either with a circular opening to fit the circular coil, or with substantially a rectangular opening to fit the rectangular coil, so as to obtain the maximum amount of contact between the coils and the walls of the casting b for the direct conduction of heat from the fluid in the thermostat into the conduit a bearing the expanded gases. If desired, these coils may be constructed of a tubular member having a cross section, as shown in Fig. 10, where one side of the coil is flattened, as at t, for providing a larger area which may contact with the walls of the castmg 6.

This construction permits almost an instantaneous transference of heat from the volatile fluid in the thermostat to the expanded gases of the refrigerating apparatus. This casting or fixture b may be of any shape desired, the essential feature being that the walls of the non-expansive chamber or feeler leg should contact with the walls of the casting b. The casting is constructed with passageways around the central opening so as to surround the non-expansive chamber with the expanded Obviously, the casting b can be con-' gases of the refrigerating apparatus. I broadly term this member a fixture, provided with a plurality of branches or passageways and arranged -to divide the gases and cause the same to be conveyed through the fixture in a plurality of streams. With this construction the transference of heat by the conduc tive principle is not interfered with by any convection currents,'and the transference of the heat by the conduction principle tends to permit practically an immediate heat transference from one fluid containing member to the other.

\ An advantage of the construction above described is that the expanded refrigerant passing through the conduit immediately effects the contents of the thermostat due to the fact that the non-expansible chamber of the thermostat is in direct metallic contact with the conduit bearing these expanded gases. The thin walls obviously permit of a quicker heat exchange than would be possible with thick walls. It will be noticed that the expansible part of the thermostat, or the bellows, is posi- L tioned away from the immediate vicinity of the conduit bearing the expanded gases, and may be affected by atmospheric temperature changes without interference from the expanded gases. The advantage of this may be best explained by going through the operation of the device.

Let us assume that the fluid in the thermostat has expanded and thrown in theelectric switch for driving the motor, which in turn drives the compressor. This causes the refrigerant to flow through the expansion coils 2 and through the conduit and the casting or fixture b. The expanded gases absorb heat from the flui'd in the thermostat and this fluid then begins to condense the heat flowing through the walls of the fixture into the expanded gases and carried away. The condensation of the fluid in the thermostat reduces the pressure inside the thermostat and when this pressure is reduced to a pre-determined point the bellows or expansible part of the thermostat is collapsed by the pressure of the spring 3 and the electric switch is thrown out, thereby stopping the motor and compressor. This immediately stops the fiow of expanded gases through the fixture adjacent the thermostat and consequently no more heat is carried from the thermostat into the fixture to be carried away by the flowing stream of expanded gases. Immediately, due to the fact that the bellows part of the walls of the thermostat is warmer or at a higher temperature than the condensed fluid inthe thermostat, the condensed fluid begins to vaporize and the pressure in the expansible chamber or bellows of the thermostat is increased. In addition, because of the fact that the bellows is removed from the vicinity of the conduit'bearing the expanded gases, the atmosphere surrounding the thermostat is free to directly affect the fluid in the thermostat, the heat from the atmosphere being absorbed by the fluid, and causing the condensed fluid to vaporize rather rapidly, thereby expanding the bellows and throwing the electric switch in for starting the machine in operation again. The fluid in the thermostat is condensed more quickly due to the fact that the non-expansible part of the thermostat is in metallic contact with the conduit bearing the expanded gases. This fluid also vaporizes more quickly when the compressor is shut ofl due to the fact that there is no interference to the transference of heat from the atmosphere surrounding the bellows part of the thermostatto the fluid within the thermostat. This gives a frequency of operation and of shorter deviation each of which is very desirof the air within the refrigerator.

What I claim is:

1. In a refrigerator control, the combination of a conduit bearing the expanded gases of the refrigerating apparatus and including a fixture having a plurality of branches for dividing the gases and conveying the same through the fixture in a plurality of streams,- a separate thin metal piece defining said branches and a fluid expansion type of thermostat provided with a depending non-expansive chamber fitted snugly in said fixture and suspended between said branches to place the chamber in immediate heat conductive relation with said thin metal piece to prevent the entrance of convection currents between said chamber and fixture.

2. In a refrigerating control, the combination of a conduit bearing the expanded gases of the refrigerating apparatus-and including a fixture having a plurality of branches for dividing the gases and conveying the same through the fixture in a plurality of streams and which is provided with a central opening around which the several streams of gases are conveyed, a separate metal sleeve defining said opening and a fluid expansion type of thermostat provided with a depending non-expansive chamber, said thermostat arseparate sleeve-like member disposed in said fixture to form branches connected to the conduits for the flow of refrigerant therethrough, said sleeve member defining an open ing in the fixture and a thermostat provided with a non-expansive chamber which 1s dlsposed in said opening and in direct heat conducting contact with the said separate sleevelike member.

In testimony whereof I have aflixed my signature.

" PATTERSON FARMER.

ranged to be seated on said fixture and tlie-- non-expansive chamber arranged to be suspended in the central opening in the fixture to place said chamber in immediate heat conductive relation with said sleeve to prevent the entrance of convection currents between the fixture and thermostat, thereby protecting the non-expansive chamber from said convection currents.

3. In a refrigerator control, a fixture having a circumferential groove-like formation in its body, means for connecting the fixture to inlet and outlet refrigerant conduits, a 

